If this looks familiar, brother Edmund Lake's GM’s Electrovair II story sprang from an earlier experiment known as Electrovair I, which was limited in success as seen in the video.
While Electrovair I was based on a first-generation Chevrolet Corvair sedan, Electrovair II was built around a second-generation Corvair—a mildly customized ’66 four-door hardtop.
Easily the most distinctive feature of the Electrovairs was their batteries. Both used silver-zinc cells, a type more often found in aerospace and military applications. Electrovair II used 286 silver-zinc cells wired in series and arranged in 13 trays with 22 cells per tray. Seven battery trays were mounted in the front luggage compartment, while the other six trays were installed in the engine compartment out back in order to more evenly distribute their considerable weight: some 680 lbs. The total capacity of the 530-volt pack was 26.4 kWh (kilowatt-hours). For comparison’s sake, the 2022 Chevy Bolt EV features a 65-kWh battery in a more space-efficient package.
With five of the six battery trays in the rear engine compartment removed, we get a decent view of the motor, a 115-hp four-pole, three-phase induction unit built by GM’s Delco Products Division and coupled to a specially engineered transaxle. The power inverter, motor controller, and oil cooling system were tucked away in the rear compartment as well, leaving the cabin free to accommodate the usual five passengers.
Road performance, which included a 0-to-60 mph time of 16.7 seconds, was described as similar to a production Corvair with automatic transmission, although Electrovair II’s top speed was restricted to 80 mph by the motor’s 13,000 rpm limit. With 680 lbs of batteries, 315 lbs of electronics and cooling gear, and a 130 lbs of motor, the Electrovair II’s greatest handicap on the highway was its weight: around 3400 lbs, some 800 lbs heftier than a production Corvair.
There were other problems, too. Range was limited to 40 to 80 miles, due in part to a lack of regenerative braking, which the project engineers declined to pursue. (They saw regen braking as mainly a means to replace conventional engine braking, not as an energy source.) GM’s windup report from the project (SAE no. 670175) also cited long charging times of six to eight hours, limited charging cycles and resultant short battery life, and high materials cost as obstacles to further EV development at that time. But then, that was the state of the art in 1966. By the way, Electrovair II is still around in fine shape and can be seen in the automaker’s private vehicle collection at the GM Heritage Center in Sterling Heights, Michigan.
Full story and credits. Thanks Edmund Lake and Macs Motor City!